1. Field of the Invention
This invention relates to a folding knife and, more particularly, to an improved locking mechanism for a folding knife.
2. Prior Art
It is common practice for folding knives to have locking mechanisms. The locking mechanism is necessary to keep the knife firmly in the open position when in use and to keep it from inadvertently opening when intended to be closed. Most locking mechanisms use a spring element, or spring biased element, moving in the plane of the knife as a locking element. U.S. Pat. No. 1,365,487 granted to Hallverson and U.S. Pat. No. 1,734,126 granted to Guttzeit are examples.
Another type of known locking mechanism moves laterally to the plane of the knife. Examples include: U.S. Pat. No. 1,521,778 granted to McLay; U.S. Pat. No. 4,896,424 granted to Walker; and U.S. Pat. No. 5,699,615 granted to Chen. McLay provides a three-piece side panel, one piece of which is a spring-biased lever having a locking flange at one end. The flange is moved into and out of apertures in the tang of the blade to effect locking. Such movement is produced by a plate on the opposite end of the lever. Inadvertent squeezing of the plate could cause closure of the blade, perhaps on the fingers of the user. Walker and Chen both provide a deflectable spring lock internal to the knife handle. Both also require an extra element for the locking mechanism in addition to their side panels. And, in each, the tip of the spring contacts directly with the blade to effect locking.
An improvement over the aforementioned prior art is the locking mechanism disclosed in U.S. Pat. No. 6,490,797 granted to Lake, the present inventor. The mechanism in Lake is a blade lock wherein the spring which biases the lock into locking engagement with the blade is a part of one of the side panels of the folding knife. This blade lock is a replaceably mounted, wear resistant disc coacting with a conical recess provided in the end face of the blade so that as the disc wears, it maintains an efficacious lock merely by seating deeper into the recess. Although Lake is a significant improvement over the prior art, manufacturing of the coacting disc and conical recess requires a level of precision that makes it costly to produce.
There is a need for a folding knife that is safe, wear resistant, and simplistic in design; therefore, inexpensive to manufacture.